370 research outputs found

    Prospects and limitations of heavy mineral analyses to discriminate preglacial/glacial transitions in Pleistocene sedimentary successions

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    The present study revolves around the identification of the stratigraphical boundary between Pleistocene formations that formed prior to the first advance of the Scandinavian ice sheet (Early Pleistocene, i.e., the so-called preglacial) and the overlying, glacially derived deposits (Middle Pleistocene). In particular, it focuses on variation in heavy mineral assemblages, which are an important tool for stratigraphers. The Neogene basement, described here, was most often the source of material that was redeposited by Early Pleistocene rivers. The geological structure and Early Pleistocene palaeogeographical scenarios for various Polish regions are discussed. Moreover, comparisons with other European preglacial formations are carried out. The mineral spectrum of Lower Pleistocene deposits is largely dependent of rocks of the Neogene and Mesozoic basement. If the incision of ancient catchments was into terrigenous rocks, the stratigraphical boundary between preglacial and glacial formations is easily determined with the help of a heavy mineral analysis. As a rule, this coincides with a noticeable change from resistant to non-resistant mineral associations. Such cases are noted for successions in central Poland and eastern England. On the other hand, outcrops of igneous or metamorphic rocks exist within preglacial river catchments in most parts of Europe. They were the local sources of non-resistant heavy minerals long before their glacial supply from the Baltic Shield. In these cases, mineralogical analysis fails in the search for the Early/Middle Pleistocene transition

    ANALIZA ROZWIĄZAŃ PLATFORM SENSORYCZNYCH DO ZASTOSOWANIA W INTERNECIE RZECZY

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    The main purpose of the work was to analyze sensory platform solutions for use on the Internet of Things. Emphasis was placed on the literature study on Sensor Platforms, Internet of Things, Bluetooth Low Energy Communication Protocol, serial digital and analog interfaces most commonly used in sensory platforms. Analysis of sensory platform solutions was carried out in terms of their functionality and efficiency. The SensorTag CC2650 sensing platform by Texas Instruments, turned out to be the best and has been used to build the hub model. The hub model was based on hardware and software implementation, which resulted in the expansion of the sensor platform with 6 additional analog inputs and a Bluetooth Low Energy data transmission profile. Testing the correctness of the software produced in the laboratory environment has made it possible to determine the correct functioning of the concentrator model.Głównym celem pracy była analiza rozwiązań platform sensorycznych do zastosowania w Internecie Rzeczy. Nacisk położony został na studium literaturowe dotyczące platform sensorycznych, Internetu Rzeczy, protokołu komunikacyjnego Bluetooth w standardzie Low Energy, szeregowych interfejsów cyfrowych oraz analogowych najczęściej stosowanych w platformach sensorycznych. Analiza rozwiązań platform sensorycznych przeprowadzona była pod kątem ich funkcjonalności oraz wydajności. Najlepszą okazała się platforma sensoryczna SensorTag CC2650, firmy Texas Instruments, którą wykorzystano do budowy modelu koncentratora. Wykonanie modelu koncentratora opierało się na realizacji sprzętowej oraz programowej, którego efektem było rozszerzenie platformy sensorycznej o 6 dodatkowych wejść analogowych oraz profil transmisji danych w standardzie Bluetooth Low Energy. Testowanie poprawności działania wytworzonego oprogramowania w środowisku laboratoryjnym pozwoliło na stwierdzenie poprawności działania modelu koncentratora

    Demetrius the Besieger

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    Upnp-Based Discovery And Management Of Hypervisors And Virtual Machines

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    The paper introduces a Universal Plug and Play based discovery and management toolkitthat facilitates collaboration between cloud infrastructure providers and users. The presentedtools construct a unified hierarchy of devices and their management-related services, thatrepresents the current deployment of users’ (virtual) infrastructures in the provider’s (physical)infrastructure as well as the management interfaces of respective devices. The hierarchycan be used to enhance the capabilities of the provider’s infrastructure management system.To maintain user independence, the set of management operations exposed by a particulardevice is always defined by the device owner (either the provider or user)

    BADANIE WPŁYWU POŁĄCZEŃ KLEJOWYCH NA POMIAR WŁAŚCIWOŚCI FIZYCZNYCH ELEMENTÓW KONSTRUKCYJNYCH ZA POMOCĄ ŚWIATŁOWODOWEJ SIATKI BRAGGA

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    The research presents the analysis of the influence of the glue connection on the measurement of elongation of stainless steel and aluminum samples by means of fiber Bragg grating (FBG) with uniform fibers used as a measuring transducer. Research indicates two possible factors affecting the deformation of the transmission spectrum obtained during elongation measurement. One of them is the type of adhesive that is used to make the connection between the fiber Bragg grating and the tested sample. The second possible factor is method of connection's execution. The need for research on glue connection resulted from the formation of defects mainly in the form of numerous side bands visible in the transmission spectrum during the measurement of elongations. The test results were presented in the form of graphs obtained on the basis of transmission characteristic.W pracy przedstawiono analizę wpływu połączenia klejowego na pomiar wydłużenia próbek ze stali nierdzewnej i aluminium za pomocą  światłowodowej siatki Bragga (FBG) o jednolitych włóknach wykorzystanej jako przetwornik pomiarowy. Badania wskazują na dwa możliwe  czynniki wpływające na deformacje widma transmisyjnego otrzymywanego podczas  pomiaru wydłużenia. Jednym z nich jest rodzaj kleju jaki wykorzystuje się do wykonania połączenia pomiędzy światłowodową siatką Bragga, a badaną próbka. Drugim możliwym czynnikiem jest sposób wykonania połączenia. Potrzeba badań nad połączeniem klejowym wynikła z powstawania defektów głównie w formie licznych wstęg bocznych, widocznych na widmie transmisyjnym podczas pomiaru wydłużeń. Wyniki badań zostały przedstawione w formie wykresów uzyskanych na podstawie widm transmisyjnych

    Evolution of Early Pleistocene fluvial systems in central Poland prior to the first ice sheet advance – a case study from the Bełchatów lignite mine

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    Deposits formed between the Neogene/Pleistocene transition and into the Early Pleistocene have been studied, mainly on the basis of drillings and at rare, small outcrops in the lowland part of Polish territory. At the Bełchatów lignite mine (Kleszczów Graben, central Poland), one of the largest opencast pits in Europe, strata of this age have long been exposed in extensive outcrops. The present paper is based on our field studies and laboratory analyses, as well as on research data presented by other authors. For that reason, it can be seen as an overview of current knowledge of lowermost Pleistocene deposits at Bełchatów, where exploitation of the Quaternary overburden has just been completed. The results of cartographic work, sedimentological, mineralogical and palynological analyses as well as assessment of sand grain morphology have been considered. All of these studies have allowed the distinction of three Lower Pleistocene series, i.e., the Łękińsko, Faustynów and Krzaki series. These were laid down in fluvial environments between the end of the Pliocene up to the advance of the first Scandinavian ice sheet on central Poland. The following environmental features have been interpreted: phases of river incision and aggradation, changes of river channel patterns, source sediments for alluvia, rates of aeolian supply to rivers and roles of fluvial systems in morphological and geological development of the area. The two older series studied, i.e., Łękińsko and Faustynów, share common characteristics. They were formed by sinuous rivers in boreal forest and open forest environments. The Neogene substratum was the source of the alluvium. The younger series (Krzaki) formed mainly in a braided river setting, under conditions of progressive climatic cooling. Over time, a gradual increase of aeolian supply to the fluvial system can be noted; initially, silt and sand were laid down, followed by sand only during cold desert conditions. These fluvio-periglacial conditions are identified in the foreground of the advance of the oldest ice sheet into this part of central Poland. The series studied have been compared with other fluvial successions which accumulated in the Kleszczów Graben during subsequent glaciations so as to document general changes in fluvial systems as reactions to climatic evolution. Thus, a palaeoenvironmental scenario has emerged which could be considered to be characteristic of central Poland during the Early Pleistocene

    The possibility of application of Sørensen and Renkonen indexes in the study of winter avifauna in small plots of the urban green areas

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    Quantitative studies of winter avifauna (1999/2000) were conducted in three fragments of urban green areas in central Poland. Two observers independently controlled three plots six times, doing two subsequent counts (10 ha/1.5 hour) on the same day. All visits that were carried out in the same plot by the same observer during the same time of day were defined as a "survey". Differences between maximum and minimum values of similarity in species composition (Sørensen index - QS) and dominance structures (Renkonen index - Re) between two plots during all "surveys" ranged from 8.4 to 11.9% (QS) and from 11.8 to 22.4% (Re). Coefficients of variation (CV) for values of Sørensen and Renkonen indexes obtained for similarity of winter avifauna between two plots during all "surveys" ranged from 4.9 to 7.6% (QS) and from 8.9 to 14.1% (Re). Significant differences were found in one case between values of similarity in species composition (QS) obtained by two observers between two different plots (Mann-Whitney test, U = 0.0, n = 8, P = 0.02). The results show that there is no possibility to estimate clearly the similarity of dominance structure (Re) and, to a lesser degree, species composition (QS) of winter avifauna between two small fragments of the urban green areas

    ANALIZA WŁAŚCIWOŚCI METROLOGICZNYCH SIATEK BRAGGA ZE STAŁYM I ZMIENNYM OKRESEM

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    The paper presents periodic structures in terms of metrological properties in the distinction for a fiber Bragg grating (FBG) with a constant and changeable period. The process of their formation and characteristics as well as applications in many areas have been described. On the basis of the literature, the results of research and measurements of measurable quantities such as temperature and stress made by periodic structures applied to the fiber of the optical fiber are presented. Analysis of the presented measurements allowed to mark the ranges and accuracy of measurements of individual applications.W pracy przedstawiono struktury periodyczne pod kątem własności metrologicznych w rozróżnieniu na światłowodowe siatki Bragga (FBG – ang.: Fiber Bragg Grating) o stałym i zmiennym okresie. Opisano proces ich powstawania oraz cechy charakterystyczne jak i zastosowania w wielu dziedzinach. W oparciu o literaturę zaprezentowano wyniki badań i pomiarów takich wielkości mierzalnych jak temperatura i naprężenie dokonywanych strukturami periodycznymi naniesionymi na włókno światłowodu. Analiza zaprezentowanych pomiarów pozwoliła nakreślić zakresy oraz dokładności pomiarów poszczególnych aplikacji

    Frequency-Domain Modeling of OFDM Transmission with Insufficient Cyclic Prefix using Toeplitz Matrices

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    A novel mathematical framework is proposed to model Intersymbol Interference (ISI) phenomenon in wireless communication systems based on Orthogonal Frequency Division Multiplexing (OFDM) with or without cyclic prefix. The framework is based on a new formula to calculate the Fast Fourier Transform (FFT) of a triangular Toeplitz matrix, which is derived and proven in this paper. It is shown that distortion inducted by the ISI from a given subcarrier is the most significant for the closest subcarriers and the contribution decays as the distance between subcarriers grows. According to numerical experiments, knowledge of ISI coefficients concentrated around the diagonal of Channel Frequency Response (CFR) matrix improves the receiver's error floor significantly. The potential use of the framework for real-time frequency domain channel simulation was also investigated and demonstrated to be more efficient than conventional time domain Tapped Delay Line (TDL) model when a number of simulated users is high.Comment: Conference: IEEE VTC-Fall 2018, 5 pages, 3 figure
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